--- scripts/watcher.py
+++ scripts/watcher.py
@@ -51,6 +51,8 @@
 LOGS_DIR = SYSTEM_DIR / "logs"
 RECALL_MSG = "Continue SESSION 2147483647"
 CHECK_INTERVAL = 30  # 秒
+# host 8568：DISPLAY 唔准寫死。由 env 攞；冇就 fallback ':99' 並一定 log（唔准靜靜 fallback）。
+DISPLAY = os.environ.get("DISPLAY") or ":99"
 
 def load_seats():
     seats = {}
@@ -116,7 +118,7 @@
         result = subprocess.run(
             ['xdotool', 'search', '--onlyvisible', '--name', 'Arena'],
             capture_output=True, text=True, timeout=5,
-            env={**os.environ, 'DISPLAY': ':99'}
+            env={**os.environ, 'DISPLAY': DISPLAY}
         )
         wids = result.stdout.strip().split()
         if not wids:
@@ -127,20 +129,20 @@
             geom = subprocess.run(
                 ['xdotool', 'getwindowgeometry', wid],
                 capture_output=True, text=True, timeout=5,
-                env={**os.environ, 'DISPLAY': ':99'}
+                env={**os.environ, 'DISPLAY': DISPLAY}
             ).stdout
             if '1408x900' not in geom:
                 # 試較返
                 subprocess.run(
                     ['xdotool', 'windowsize', wid, '1408', '900'],
-                    timeout=5, env={**os.environ, 'DISPLAY': ':99'}
+                    timeout=5, env={**os.environ, 'DISPLAY': DISPLAY}
                 )
                 time.sleep(1)
                 # 再驗
                 geom2 = subprocess.run(
                     ['xdotool', 'getwindowgeometry', wid],
                     capture_output=True, text=True, timeout=5,
-                    env={**os.environ, 'DISPLAY': ':99'}
+                    env={**os.environ, 'DISPLAY': DISPLAY}
                 ).stdout
                 if '1408x900' not in geom2:
                     log(sid, f"🚨 window {wid} 較唔返 1408x900，呢個 cycle 唔運行")
@@ -950,7 +952,7 @@
     try:
         out = subprocess.run(['xdotool', 'search', '--name', 'Chrome'],
                            capture_output=True, text=True, timeout=5,
-                           env={**__import__('os').environ, 'DISPLAY': ':99'})
+                           env={**__import__('os').environ, 'DISPLAY': DISPLAY})
         wids = [w for w in out.stdout.strip().split('\n') if w]
         # 搵最大嗰個（browser 主視窗）
         best, best_area = None, 0
@@ -958,7 +960,7 @@
             try:
                 g = subprocess.run(['xdotool', 'getwindowgeometry', wid],
                                  capture_output=True, text=True, timeout=3,
-                                 env={**__import__('os').environ, 'DISPLAY': ':99'})
+                                 env={**__import__('os').environ, 'DISPLAY': DISPLAY})
                 for line in g.stdout.split('\n'):
                     if 'Geometry:' in line:
                         parts = line.split()[1].split('x')
@@ -978,7 +980,7 @@
         out = subprocess.run(['import', '-window', str(window_id),
                             '-crop', f'1x1+{x}+{y}', '-depth', '8', 'txt:-'],
                            capture_output=True, text=True, timeout=5,
-                           env={**__import__('os').environ, 'DISPLAY': ':99'})
+                           env={**__import__('os').environ, 'DISPLAY': DISPLAY})
         import re
         m = re.search(r'#([0-9a-fA-F]{6})', out.stdout)
         return '#' + m.group(1).lower() if m else None
@@ -1014,7 +1016,7 @@
 def _xdotool_click(window_id, x, y):
     """跟 CA：xdotool 三步點擊"""
     import subprocess, time
-    env = {**__import__('os').environ, 'DISPLAY': ':99'}
+    env = {**__import__('os').environ, 'DISPLAY': DISPLAY}
     try:
         subprocess.run(['xdotool', 'windowraise', str(window_id)], env=env, timeout=3, capture_output=True)
         time.sleep(0.2)
@@ -1142,7 +1144,7 @@
 def ca_checkbox_click(window_id, x, y):
     """CA 式：用 xdotool 做 OS 層級滑鼠點擊（唔係 DOM click）"""
     import subprocess
-    env = {'DISPLAY': ':99'}
+    env = {'DISPLAY': DISPLAY}
     try:
         subprocess.run(['xdotool', 'windowraise', str(window_id)], env={**os.environ, **env}, timeout=3, capture_output=True)
         subprocess.run(['xdotool', 'windowactivate', '--sync', str(window_id)], env={**os.environ, **env}, timeout=3, capture_output=True)
@@ -1210,6 +1212,7 @@
     log(sid, f"Profile 直接用 workspace: {profile_dir}")
 
     log(sid, f"啟動 watcher: profile={cfg['profile']}, vpn={cfg['vpn']}:{port}, url={cfg['url']}")
+    log(sid, f"DISPLAY={DISPLAY}" + ("（由 env）" if os.environ.get("DISPLAY") else "（⚠️ fallback :99：unset DISPLAY）"))
 
     with sync_playwright() as p:
         browser = None